Mining fuse



tars earns is MINING FUSE Maurice Roumazeilles, Joinville le Font, andRoger Harl, Pitres, France, assignors to Societe dite Harle Freres & Co,S. A. R. L, Pitres (Euro), France No Drawing. Application May 4, 1936,Serial No. 77,878. In France May 10, 1935 9 Claims. (Cl. 1028) Thepresent invention relates to mining fuses pie, tricresylandtriphenylphosphates with or and especially mining fuses for firingliquid without the admixture of a filler such as, preferoxygencartridges. ably, lamp black. In order to prevent the fuse The fusesthat are employed at the present from adhering while being wound aboutitself,

im for firin iq i xy n car rid es have th it may be covered with a layerof powdered mica, 5 drawback that they. do not prevent the formationwhich is preferably applied immediately after of external sparks which,in the presence of the being coated and while the coating is still in aoXygen Stream. considerably elera e e r wet state. The mixture thusformed is perfectly of combustion and therefore endanger t e li stableand neutral at temperatures below 150 C.,

10 Of the person that 13 making use Of them. and it is especially suitedfor application upon 10 It has been endeavoured to obv ate t s draW- thefuse at lower temperatures more compatible ba k by imp at n t s 5 Withsaline with the prevention of deterioration of the solutions, or, in amore g ne l an er, p e powder comprising the combustible core of thenating masses the decomposition of which, under fu e (belcw 105 Anctherimportant prop- 15 the efiect of the heat resulting from the ccmbust f t1 coating is t t it may be aption of the black powder core and from theexplied in ery thin layers to the fuse at these ternal sparks, produceseither the formation of a preferred temperatures. protective andextinguishing gaseous layer or the wh brgught t temperatures above 150C, vitrification of the impregnating s, giving the by the heat given ofiby the combustion of the 20 same result. fuse, the mixture comprisingthe coating Will 20 It was also suggested to make fi eproof comp form ashell which normally is incombustible, sitions of matter, especially forthe manufacture and, While melting 1 gradually Coat the f e Ofinsulating materials for use in Othel' branches as the norma co nbustionof the latter proceeds of t e instance TOT making electrical Thus, thecoating provided in accordance with conductors. T e e COmDOSitiOHScfinsist 0f the present invention possesses the following detur s f p up d of defines of ru r and sirable properties. In the heated state, itis liqof fillers. They may so (301151813 0f the O OW- uid at thepreferred temperatures of application,

ing matters: or otherwise the powder core would be deterio- Resinsplastified by a tricresylp osphate; rated, and it is sufficiently liquidto coat an ordi- Gutta-percha mixed with rubber and resin; fuse with avery thin uniform shell t 30 Hydmcarbons mixed With rubber d a ho 0gveryrapid speed. In the cold state, the coating enous naphthalene; isadherent to the fuse base, flexible, and hard Rubber mixtures conta naliphat c polyenough at normal temperatures to prevent stickmericcompounds having a high pe ce ta 0f ing to itself when wound, or toother substances chlorine and aromatic chlorinated hydrocarbons. withwhich it may come in contact. The cover- 35 But these compositions ofmatter do not ing is also very homogeneous, stable, imper possess theproperties above stated necessary for able, and insoluble. making miningfuses more especially intended One specific example of the reduction ofthe for firing liquid oxygen cartridges. present invention to practiceis as follows: 4500 The object of the present invention is to progr. oftetrachloronaphthalene are melted at a 40 vide a mining fuse whichavoids all the drawtemperature of approximately 120, that is, somebacksabove mentioned. what above its melting point; 400 gr. of tricresyl- Tothis effect, the present invention contemphosphate, such as ammoniumtricresylphosplates the coating of a mining fuse having a phate, arethen added; then there is added with combustible core of the usual typewith a thin, constant stirring 600 gr. of chlorinated rubber; flexibleand non-viscous coating or shell com-e and about 200 gr. of lamp blackor any other posed of a chloronaphthalene, having a high suitablefilling material may be added to the percentage of chlorine, with theadmixture of mixture. When thoroughly mixed the product chlorinatedrubber, this latter ingredient repremay be applied directly to the fusebase,--which senting less than 30% (preferably in the neighis preferablyalready tarred as in the usual case, 50

borhood of 12%) by weight of the mixture, and by immersion of the fusein the vessel containacting as a plastifier for and at the same time ingthe molten coating material. fireproofing the coating. It should also benoted that the mixture above If desired, additional plastifyingsubstances indicated can be utilized in combination with may be added tothis mixture, such as for exampitches, tars, resins, plastic matter andthe like. 55

In a general manner, while we have, in the above description, disclosed.what we deem to be an efficient embodiment of the present invention, itshould be well understood that we do not wish to be limited thereto asthere might be changes made therein Without departing from the principleof the present invention as comprehended within 'the scope of theappended claims.

What we claim is: 7

1. A safety fuse particularly adapted for use in connection with thefiring of liquid oxygen cartridges in mining operations or the like,comprising a fuse having a combustible core and having a thin, flexible,non-viscous coating thereon composed of a mixture oftetrachloronaphthalene and chlorinated rubber, the latter ingredient notexceeding 30% by weight of the total mass of said mixture.

2. A safety fuse particularly adapted for use in connection with thefiring of liquid oxygen cartridges in mining operations or the like,comprising a fuse having a combustible core and having a thin, flexible,non-viscous coating thereon composed of a mixture oftetrachloronaphthalene and chlorinated rubber, the latter ingredientcfomprising approximateiy 12% by Weight'of the'total mass of saidmixture.

3. A safety fuseparticularly adapted for use in connection with thefiring of liquid oxygen cartridges in mining operations or the like,comprising a fuse having a combustible core and having a thin, flexible,non-viscous coating ,7

thereon composed of a mixture of not under 70% by weight oftetrachloronaphthalene and not over 30% by weight of chlorinated rubber;

together with an additional plastifier consisting of one selected fromthe following grcup:- tricresylphosphates and triphenylphosphates.

4. A safety fuse particularly adapted for use in connection with thefiring of liquid oxygen cartridges in mining operations or the like,com" prising a fuse having a combustible core and having a thin,flexible, non-viscous coating thereon composed of a mixture of not under70% by Weight of tetrachloronaphthalene and not over 30% by weight ofchlorinated rubber; together with an additional plastifier consisting ofammonium tricresylphosphate.

5. A safety fuseparticularly adapted for use in connection with thefiring of liquid oxygen car tridges in mining operations or the like,comprising a fuse having a combustible core and having a thin,flexiblanon-viscous coating thereon composed of a mixture of not under70% by weight of tetrachloronaphthalene and not over 30% by weight ofchlorinated rubber; together with a having a thin,

filler and an additional plastifier consisting of one selected from thefollowing group:-tricresylphosphates and triphenylphosphates.

' 6. A safety fuse particularly adapted for use in connection with thefiring of liquid oxygen cartridges in mining operations or the like,comprising a fuse, having a combustible core and having a thin,flexible, non-viscous coating thereon composed of a mixture of not under70% by weight of tetrachloronaphthalene and not over 30% by weight ofchlorinated rubber; together with a filler consisting of lamp black andan additional plastifier consisting of one selected from the followinggroup:-tricresylphosphates and triphenylphosphates.

7. A safety fuse particularly adapted for use in connection with thefiring of liquid oxygen cartridges in mining operations or the like,comprising a fuse having a combustible core and having a thin, flexible,non-viscous coating thereon composed of a mixture of not under 70% byWeight of tetrachloronaphthalene and not over 30% by weight ofchlorinated rubber; together with an additionalplastifler consisting ofa tricresylphosphate; and an outer adhering layer of powdered mica.

8. A safety fuse particularly adapted for use in connection with thefiring of liquid oxygen cartridges in mining operations or the like,comprising a fuse having a combustible core and flexible, non-viscouscoating thereon composed of a mixture of the following ingredients inthe proportions substantially as set forth:-

Parts Tetrachloronaphthalene h 45 Chlorinated rubber 6Atricresylphosphate 4 A filler 2 Chlorinated rubber 6 Ammonium tricresylphosphate 4 Lamp black 2 ROUMAZEHJLEZS. ROGER HARLE.

